I think that SSA is a commonly used abbreviation so Colt doesn't have any claim on it trademark wise. Think Social Security Administration, Self Storage Association, Soaring Society of America and a host of others. As for The single action army it was a military classification and never a trade mark. There are a number of firearms manufactured with the type being Single action army. Uberty, Eaa, Genitron, Cimarron Arms and others. The type single action army is much like the type 1911 or the type AR15 as they designate a type of gun.
Well, first off, it's SAA, which stands for Single Action Army, not SSA.
Secondly, you are wrong. Single Action Army is a registered trademark of the Colt company.
See it for yourself at the Colt website. That R inside a circle is the symbol for a Registered Trademark. You may also notice the R in the circle by Colt's logo, which is also trademarked.
http://www.colt.com/Catalog/Revolvers/Single-Action-Army
Here is a definition.
https://en.wikipedia.org/wiki/Trademark
A trademark is typically a name, word, phrase, logo, symbol, design, image, or a combination of these elements. There is also a range of non-conventional trademarks comprising marks which do not fall into these standard categories, such as those based on color, smell, or sound (like jingles). Trademarks which are considered offensive are often rejected according to a nation's trademark law.
As for being commonly used, that is the whole point of trademark law. When other companies use trademarked names and designs, it is up to the trademark holder to defend their trademark. If they do not defend their trademark, the courts will rule that the trademark no longer exists. Unlike patents, which expire after a certain amount of time, trademarks last forever as long as the trademark holder maintains it. Maintaining a trademark includes taking legal action against trademark infringements.
Probably the most famous trademark in the world is the Coca Cola logo. Next time you open a Coke, take a look and you will see the little trademark symbol.
Firearm types such as the 1911 or the AR15 have nothing to do with trademarks. They are simply military designations. The military designation of the SAA in 1873 was Colt Army Revolver, Caliber .45.
At some point Colt obtained a Trademark on the name Single Action Army, and they have been maintaining their trademark ever since. Uberti, and Peitta, NEVER advertise their products as Single Action Army, or SAA, because they know Colt will sue the pants off of them. Colt successfully sued American Western Arms a number of years ago for trademark infringement.
Patents are one thing. They expire. The patents on the SAA expired long ago, so anybody can make a revolver that looks like a SAA. The copies can even have internal parts that function exactly like the originals, because the patents expired long ago. But they cannot use the name Single Action Army or SAA because those names are trademarked.
You will never see this stamped on the barrel of any firearm unless it was made by Colt.
I am pretty sure Colt has trademarked the Rampant Pony too. You will not see it on any products other than those made by Colt.